bool zmq::mux_t::read (message_t *msg_)
{
// Underlying layers work with raw_message_t, layers above use message_t.
// Mux is the component that translates between the two.
raw_message_t *msg = (raw_message_t*) msg_;
// Deallocate old content of the message.
raw_message_destroy (msg);
// Round-robin over the pipes to get next message.
for (int to_process = pipes.size (); to_process != 0; to_process --) {
bool retrieved = pipes [current]->read ((raw_message_t*) msg_);
current ++;
if (current == pipes.size ())
current = 0;
if (retrieved)
return true;
}
// No message is available. Initialise the output parameter
// to be a 0-byte message.
raw_message_init (msg, 0);
return false;
}
// Same as above, however, the message is rebuilt from the supplied
// buffer. See appropriate constructor for discussion of buffer
// deallocation mechanism.
inline void rebuild (void *data_, size_t size_, free_fn *ffn_)
{
raw_message_destroy (this);
raw_message_init (this, data_, size_, ffn_);
}
// Creates message from the supplied buffer. 0MQ takes care of
// deallocating the buffer once it is not needed. The deallocation
// function is supplied in ffn_ parameter. If ffn_ is NULL, no
// deallocation happens - this is useful for sending static buffers.
inline message_t (void *data_, size_t size_, free_fn *ffn_)
{
raw_message_init (this, data_, size_, ffn_);
}
// Destroys old content of the message and allocates buffer for the
// new message body. Having this as a separate function allows user
// to reuse once-allocated message for multiple times.
inline void rebuild (size_t size_)
{
raw_message_destroy (this);
raw_message_init (this, size_);
}
// Creates message size_ bytes long.
inline message_t (size_t size_)
{
raw_message_init (this, size_);
}